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authorChristoph Hellwig <hch@lst.de>2015-01-18 16:16:29 +0100
committerJens Axboe <axboe@fb.com>2015-02-05 09:30:37 -0700
commitddad8dd0a162fde61646a627a3017c258601dc8a (patch)
tree62a0c931c0efb7cd86457e1908ceb1655997c595 /block/blk-map.c
parent42d2683a2704ef4bbbb07fd0b9486ab312dd8c56 (diff)
downloadkernel-ddad8dd0a162fde61646a627a3017c258601dc8a.tar.gz
block: use blk_rq_map_user_iov to implement blk_rq_map_user
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-map.c')
-rw-r--r--block/blk-map.c137
1 files changed, 13 insertions, 124 deletions
diff --git a/block/blk-map.c b/block/blk-map.c
index f890d4345b0c..152a5fe5d85e 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -39,130 +39,6 @@ static int __blk_rq_unmap_user(struct bio *bio)
return ret;
}
-static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
- struct rq_map_data *map_data, void __user *ubuf,
- unsigned int len, gfp_t gfp_mask)
-{
- unsigned long uaddr;
- struct bio *bio, *orig_bio;
- int reading, ret;
-
- reading = rq_data_dir(rq) == READ;
-
- /*
- * if alignment requirement is satisfied, map in user pages for
- * direct dma. else, set up kernel bounce buffers
- */
- uaddr = (unsigned long) ubuf;
- if (blk_rq_aligned(q, uaddr, len) && !map_data)
- bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
- else
- bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);
-
- if (IS_ERR(bio))
- return PTR_ERR(bio);
-
- if (map_data && map_data->null_mapped)
- bio->bi_flags |= (1 << BIO_NULL_MAPPED);
-
- orig_bio = bio;
- blk_queue_bounce(q, &bio);
-
- /*
- * We link the bounce buffer in and could have to traverse it
- * later so we have to get a ref to prevent it from being freed
- */
- bio_get(bio);
-
- ret = blk_rq_append_bio(q, rq, bio);
- if (!ret)
- return bio->bi_iter.bi_size;
-
- /* if it was boucned we must call the end io function */
- bio_endio(bio, 0);
- __blk_rq_unmap_user(orig_bio);
- bio_put(bio);
- return ret;
-}
-
-/**
- * blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
- * @q: request queue where request should be inserted
- * @rq: request structure to fill
- * @map_data: pointer to the rq_map_data holding pages (if necessary)
- * @ubuf: the user buffer
- * @len: length of user data
- * @gfp_mask: memory allocation flags
- *
- * Description:
- * Data will be mapped directly for zero copy I/O, if possible. Otherwise
- * a kernel bounce buffer is used.
- *
- * A matching blk_rq_unmap_user() must be issued at the end of I/O, while
- * still in process context.
- *
- * Note: The mapped bio may need to be bounced through blk_queue_bounce()
- * before being submitted to the device, as pages mapped may be out of
- * reach. It's the callers responsibility to make sure this happens. The
- * original bio must be passed back in to blk_rq_unmap_user() for proper
- * unmapping.
- */
-int blk_rq_map_user(struct request_queue *q, struct request *rq,
- struct rq_map_data *map_data, void __user *ubuf,
- unsigned long len, gfp_t gfp_mask)
-{
- unsigned long bytes_read = 0;
- struct bio *bio = NULL;
- int ret;
-
- if (len > (queue_max_hw_sectors(q) << 9))
- return -EINVAL;
- if (!len)
- return -EINVAL;
-
- if (!ubuf && (!map_data || !map_data->null_mapped))
- return -EINVAL;
-
- while (bytes_read != len) {
- unsigned long map_len, end, start;
-
- map_len = min_t(unsigned long, len - bytes_read, BIO_MAX_SIZE);
- end = ((unsigned long)ubuf + map_len + PAGE_SIZE - 1)
- >> PAGE_SHIFT;
- start = (unsigned long)ubuf >> PAGE_SHIFT;
-
- /*
- * A bad offset could cause us to require BIO_MAX_PAGES + 1
- * pages. If this happens we just lower the requested
- * mapping len by a page so that we can fit
- */
- if (end - start > BIO_MAX_PAGES)
- map_len -= PAGE_SIZE;
-
- ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
- gfp_mask);
- if (ret < 0)
- goto unmap_rq;
- if (!bio)
- bio = rq->bio;
- bytes_read += ret;
- ubuf += ret;
-
- if (map_data)
- map_data->offset += ret;
- }
-
- if (!bio_flagged(bio, BIO_USER_MAPPED))
- rq->cmd_flags |= REQ_COPY_USER;
-
- return 0;
-unmap_rq:
- blk_rq_unmap_user(bio);
- rq->bio = NULL;
- return ret;
-}
-EXPORT_SYMBOL(blk_rq_map_user);
-
/**
* blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
* @q: request queue where request should be inserted
@@ -241,6 +117,19 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_rq_map_user_iov);
+int blk_rq_map_user(struct request_queue *q, struct request *rq,
+ struct rq_map_data *map_data, void __user *ubuf,
+ unsigned long len, gfp_t gfp_mask)
+{
+ struct sg_iovec iov;
+
+ iov.iov_base = (void __user *)ubuf;
+ iov.iov_len = len;
+
+ return blk_rq_map_user_iov(q, rq, map_data, &iov, 1, len, gfp_mask);
+}
+EXPORT_SYMBOL(blk_rq_map_user);
+
/**
* blk_rq_unmap_user - unmap a request with user data
* @bio: start of bio list